diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2020-01-14 22:17:25 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-01-24 09:46:45 +0100 |
| commit | b7bf9908e17c4dc4b80876f299ac03ddf188efd9 (patch) | |
| tree | 5b37db7eb28823b29b26e40e1b93092ecdf6b300 /fs/overlayfs/inode.c | |
| parent | 1b81dddd354cf304574d79004400a6385613ae4e (diff) | |
ovl: fix corner case of non-constant st_dev;st_ino
On non-samefs overlay without xino, non pure upper inodes should use a
pseudo_dev assigned to each unique lower fs, but if lower layer is on the
same fs and upper layer, it has no pseudo_dev assigned.
In this overlay layers setup:
- two filesystems, A and B
- upper layer is on A
- lower layer 1 is also on A
- lower layer 2 is on B
Non pure upper overlay inode, whose origin is in layer 1 will have the
st_dev;st_ino values of the real lower inode before copy up and the
st_dev;st_ino values of the real upper inode after copy up.
Fix this inconsitency by assigning a unique pseudo_dev also for upper fs,
that will be used as st_dev value along with the lower inode st_dev for
overlay inodes in the case above.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/inode.c')
| -rw-r--r-- | fs/overlayfs/inode.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 60f7b8f092f2..79e8994e3bc1 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -121,13 +121,12 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid) */ stat->dev = dentry->d_sb->s_dev; stat->ino = dentry->d_inode->i_ino; - } else if (fsid) { + } else { /* * For non-samefs setup, if we cannot map all layers st_ino * to a unified address space, we need to make sure that st_dev - * is unique per lower fs. Upper layer uses real st_dev and - * lower layers use the unique anonymous bdev assigned to the - * lower fs. + * is unique per underlying fs, so we use the unique anonymous + * bdev assigned to the underlying fs. */ stat->dev = OVL_FS(dentry->d_sb)->fs[fsid].pseudo_dev; } @@ -143,7 +142,6 @@ int ovl_getattr(const struct path *path, struct kstat *stat, struct path realpath; const struct cred *old_cred; bool is_dir = S_ISDIR(dentry->d_inode->i_mode); - bool samefs = ovl_same_fs(dentry->d_sb); int fsid = 0; int err; bool metacopy_blocks = false; @@ -198,13 +196,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, (!ovl_verify_lower(dentry->d_sb) && (is_dir || lowerstat.nlink == 1))) { fsid = ovl_layer_lower(dentry)->fsid; - /* - * Cannot use origin st_dev;st_ino because - * origin inode content may differ from overlay - * inode content. - */ - if (samefs || fsid) - stat->ino = lowerstat.ino; + stat->ino = lowerstat.ino; } /* |